Wind turbine noise : assessment an planning

Abstract

Issues relating to noise from wind farm developments are currently not being dealt with either accurately or consistently throughout Ireland. Impact assessment studies show a high degree of variation throughout the country as also do the planning limits imposed by planning authorities. These shortfalls may be attributed to the absence of, and also the misinterpretation of relevant guidance for wind farm developments. Much guidance is available nationally and internationally for industrial applications but wind turbine noise disturbance is quite unique and is not adequately addressed by common practices. Wind farm developments are normally located in quiet rural areas and although the noise generated may not necessarily be very high it has the potential to cause considerable nuisance. The preservation of natural quiet in areas of existing low background noise levels has been recognised in European environmental legislation [2002/49/EC] and its implementation is being gradually implemented in the EU and Ireland. Wind turbine noise has evolved rapidly in recent years with taller and larger turbines with complex noise profiles. Based on the findings of this study, a more defined approach is required in order that potential noise problems are identified and addressed at the planning stage. Some of the major recommendations include • The requirement of comprehensive baseline studies for all developments over a range of wind speeds and atmospheric conditions • The use of the L90 noise descriptor for noise measurement for the baseline study and similar noise measurement procedures to be repeated once the wind farm is operational • The necessity to conduct noise prediction modelling over a wide range of wind speeds to account for the variable noise characteristics of newer turbines Noise limits imposed by planning authorities will need to be more defined in order to address potential noise problems. This can be achieved by setting noise limits in relation to background noise, including the requirement to conduct noise prediction and compliance assessment over a wide (but clearly defined) range of wind speeds and meteorological conditions.